'I saw a man while I was out [driving a taxi] who reminded me of me' ... Oscar Fernando Gómez Rodríguez's best shot.

When I was 18, I left Monterrey to look for work in Mazatlán, a town 12 hours away, near Mexico's west coast. But on the way I ran out of money, and ended up sleeping rough, eating whatever I could find, sleeping on street corners, just surviving. Eventually, I tried to hitch a ride to my aunt's house, not far from Mazatlán. When I finally got there, on a lorry carrying a load of strawberries, I weighed 45kg (7st).

Two decades on, I'm back in Monterrey, working as a taxi driver (and I now weigh about 110kg). One day, I saw this man while I was out driving. He reminded me of what I'd been through: first living on the streets, then doing a series of odd jobs, like street-sweeping or cleaning carpets. He had loaded his wheelbarrow with industrial waste – wood, metal, plastic – to sell to recycling companies for about three pesos (15p) a kilo. I, too, did this. As I drove past him, I noticed he had stopped to comb his hair very carefully. Intrigued, I asked if I could take his photograph: I wanted to show that even people who can't find work – who have nothing – can maintain their dignity. Often, it is all they have.

I started taking photographs when I left my aunt's town. I bought the cheapest camera I could find, a Kodak, and shot places that had been special to me, such as monuments and parks. When I got back to Monterrey, I bought a better camera, a 35mm Canon, and took more shots: rivers and landscapes at first, then wedding portraits.

When my wife and I decided to have a child, I started taking photos from the window of my taxi, to make an album to show our child what dad sees when he is out all day. Our daughter died at birth, but I carried on taking pictures: of poor people, people who have nothing. For me, the important thing is not technique or composition. It's about trying to show that the people who live the most humble lives are often the most worthy of respect."

CV

Born: Monterrey, Mexico, 1970.

Studied: "I bought a photography magazine that taught me how to click the shutter. That was all I needed."